Electronic data recorders, commonly known as black boxes, could blow the lid off unintended acceleration allegations against Toyota Motor Corp.

Typically, EDRs have worked in favor of the manufacturer in court cases where the data has been introduced, EDR experts tell Ward's.

“I would say that's probably more likely than not the case, and it comes back to the idea that there really aren't that many problems with cars,” says Rusty Haight, director of accident reconstruction firm The Collision Safety Institute.

Yet, the question remains whether the data on Toyota's EDRs will have the same redeeming effect in a growing number lawsuits it now faces as it recalls some 9.5 million vehicles linked to unintended acceleration problems worldwide.

Some of those suing Toyota allege malfunctioning electronic throttle-control systems.

Whether this issue can be disproven from Toyota's black-box data is unclear.

“I'm not sure what Toyota records in their EDRs — they haven't told us,” says Chris Medwell, a professional engineer specializing in black boxes for forensics firm Bloomberg Consulting Inc.

While the majority of cars and trucks sold in the U.S. today typically have EDRs, only General Motors Co., Ford Motor Co. and Chrysler Group LLC have allowed vehicle owners access to the data.

EDRs differ among auto makers, and even within a brand's lineup. But most record events just prior to and following a frontal crash.

EDRs typically have not been able to sufficiently record events relating to rear or side impacts.

Conditions usually recorded include accelerator- and brake-pedal positions, gear selection, vehicle speed and whether a driver was wearing a seatbelt.

But as digital memory has become cheaper, EDRs have been able to record more events, more frequently.

An example is Nissan Motor Co. Ltd.'s GT-R sports car. The GT-R has a standard data recorder for accident information, as well as a vehicle status data recorder. The VSDR continuously monitors various systems on the GT-R, says Nissan spokesman Brian Brockman.

EDRs are fed data by numerous sensors and can be positioned anywhere in a vehicle.

Toyota's EDRs are contained in airbag electronic control units, the auto maker says in a 2008 online discussion Ward's finds on the auto maker's U.S. media website.

Toyota says it began phasing in the airbag EDRs in '01 vehicles.

GM also places its EDRs in airbag-control modules, spokesman Alan Adler says.

At recent congressional hearings, Toyota officials said they would make commercially available by mid-April a tool to read their EDRs, as GM, Ford and Chrysler already do. GM's EDR data is owned by the vehicle owner, Adler says. The owner can access the data providing he can find a dealer or law-enforcement personnel with the proper tool.

The data also can be obtained by law enforcement via a subpoena, Adler says.

Toyota, and other foreign auto makers have not had such an open policy.

“Toyota will not honor EDR readout requests from private individuals or their attorneys,” Toyota says in 2008 online discussion.

The auto maker says its EDR readout tool is a “prototype,” adding there only is one such tool in the U.S. and “only specially designated Toyota personnel use it.”

Toyota says it does not have confidence in the accuracy of the readout reports generated by the tool set, as the set has not “been scientifically validated.”

Nevertheless, Medwell tells Ward's Toyota was in final negotiations with data-retrieval firm Vetronix, which since has been acquired by Robert Bosch GmbH. But the auto maker backed away after the National Highway Traffic Safety Admin. proposed rules for EDR data.

NHTSA sought comments on EDRs in 2002.

Bosch denied Ward's request for an interview about its software.

“(Toyota) said, ‘We're not going to do it until the government requires us to,’” Medwell says. “They then instituted a policy, which they haven't really changed, where they're not going to download anybody's module ever unless the police or judge orders them to.”

In an emailed response, Toyota Motor Sales U.S.A. Inc. spokesman Brian Lyons tells Ward's the auto maker “does not comment in regard to confidential future product/equipment discussions” but adds it also will download the EDR data at NHTSA's request.

NHTSA's EDR rules have been finalized and are set to take effect in September 2012 with '13 model-year vehicles.

NHTSA will not require auto makers to install EDRs but will mandate the kinds of events recorded and their frequency. NHTSA also will require data from EDRs to be accessible to owners.

Toyota says it will comply with the 2012 requirement to make a download tool commercially available, but does not address a question of what percentage of its models will have EDRs by that time.

Medwell contends EDR data is reliable and admissible in court cases.

“It has been turned away (by) courts, but it's never been because the data, itself, has been questioned,” he says. “The data itself has never been defeated as far as I know.”

Haight says sensor failures or programming errors could occur, making EDR data unreliable, but emphasizes both are extremely rare occurrences and would result in no data, vs. unreliable data, being recorded.

“If a sensor fails, you get no data,” Haight says. “The best analogy I can give is to think of a sensor like a pencil. If it fails, you run out of lead. And what do you get? You get nothing. You don't get something goofy, you get nothing.”

In a Feb. 8 online interview with website Digg, a Crestline, CA, woman injured in a Toyota asked Toyota Motor Sales U.S.A. Inc. President Jim Lentz why she could not have access to the data in her EDR, which she thought would absolve her.

“I lost my car, my health and thousands of dollars, and now you say you can't track down the cause of this problem. Why not release the electronic data?” the woman said.

Lentz offered apologies for the accident but called EDRs “experimental” and said “they are not advanced enough today to really be usable.”

In his email statement to Ward's, Lyons expands on Lentz's comment, saying Toyota's EDR system was “intended to help research and improve performance of safety systems such as airbags. It was not designed as a tool for accident reconstruction, and we do not believe it yields consistent or reliable data at this stage that would be suitable for that purpose.”